1. Field of the Invention
The present invention relates to improvements to efficiency, ecology, safety, and speed of transportation technology.
The transport of persons and cargo is currently handled by the use of: trains; bicycles, cars, trucks, trailers, busses and motorcycles operating on roads, tunnels, bridges and highways; ships, submarines boats and hover-craft in water; and airplanes, rotor-craft, dirigibles, rockets, and balloons in the air. Pipelines carry liquids and gasses. Aluminum or copper conductors transport electrical power.
Energy Requirements of Classic Transport Methods:
The minimum energy required to accelerate an object to a given speed is E=(M/2)*V*V. All of this energy is retained by the object in the form of kinetic energy unless it is lost through energy transfer such as: 1) external energy reduction due to collisions with another object or travel through a opposing force field, 2) internal energy usage such as heating due to hysteresis or shearing forces (rolling elements and brakes), 3) internal or external energy usage or storage. These well-known losses are primarily:
Aerodynamic drag (or hydrodynamic) D=A*Cd*Q, D is the drag. A is the frontal area of the object. Cd is the drag coefficient of the object and Q is the dynamic pressure equal to the one half the density of the fluid times the velocity squared. This equation is a close approximate for incompressible ideal fluids. The actual drag experienced is worse than the equation predicts because of viscosity and compressibility of air. At high speed (the speed of sound) the flow of air undergoes a transition to compressed flow. Objects traveling faster than the speed of sound experience far greater drag losses, and large amounts of heat are generated in the object by the shock wave. The top speed if an object traveling through air is mostly determined by aerodynamic forces. For the average car or truck half of the resistance is aerodynamic at a speed of 60 MPH. At 120 MPH the aerodynamic resistance increases to 3/4 of the total. Aerodynamic resistance and heating is the main obstacle to high speed travel. A car or jet airplane consumes vast quantities of fuel just to push the air (and sound waves) aside for passage. Air continually blocks travel and must be moved every step of the way draining kinetic energy from the traveling object.
Much effort has gone into reducing aerodynamic drag of aircraft and cars. The methods of this drag reduction have been to: reduce to a minimum the frontal area, the wetted area, and the drag coefficient of the body traveling through the air. Aircraft reduce drag by flying at high altitudes where the air is less dense, however engine power is also reduced. Expensive wind tunnels, or super computers are necessary tools for reduction of drag by classic methods.
Rolling resistance is more or less constant, so power absorbed varies linearly with speed. At the top speed of most vehicles rolling resistance is a small percentage of the total resistance. It is however a major obstacle to high speed travel. After aerodynamic forces rolling resistance is the next biggest obstacle to high speed travel. Drag of rolling elements is reduced by using large diameter thin, hard wheels rolling on a hard smooth surface. At high speed the centrifugal forces generated in rolling elements become extreme. Heat builds in bearings, tires, and wheels faster than it can dissipate. The limiting factor to higher speed becomes the strength of the materials, and heat buildup. Rolling elements have been used up to about 650 mph. Sustainable maximum safe speed using rolling elements is about 300 MPH. Rolling resistance is mainly due to the flexibility (hysteresis losses) of contacting elements like tires. Flexibility of rolling elements is minimized on trains. To minimize rolling resistance ride quality and rough road tolerance is compromised.
Internal friction of engine and power transmissions, while small compared to the total power produced are a significant factor and represent vast quantities of lost energy. Internal friction is present any time contacting surfaces move relative to one another. Another cause of internal resistance is the hydrodynamic shearing of lubricating and working fluids used in bearings to reduce friction. Pipe lines that carry fluids and gasses are limited in their capacity by internal friction of the fluid, and friction with the side wall of the pipe. Pressure is required to overcome losses and move a fluid through a pipe. The pressure required is dependent on the length and diameter of the pipe, the amount of flow, and the viscosity of the fluid. When the pressure required to force flow exceeds the pressure rating of the pipe, the pipe may burst. The electrical resistance of a conductor is proportional to its length. The amount of current that a wire can carry is proportional to the area of the diameter. Voltage potential is used to overcome resistance of the wire to move current. The voltage drop caused by resistance along the length of the wire is an energy loss. The lost energy is in the form of heat. Heat buildup limits the power transfer potential of a wire, if the current exceeds the rating the wire may melt or burn.
Only a small percentage of the energy that a plane or car uses is actually used to accelerate the vehicle. None of this energy is recovered when deceleration takes place, it is dissipated in the form of heat and sound as the speed is reduced.
It is well known that space craft in outer space travel with virtually no drag; the speed is limited only by energy requirements. Once a spacecraft is up to speed it can coast for years at ultra high speed using no energy for propulsion. The fuel required to get a space vehicle into orbit weighs many times more than the vehicle. None of the energy used is recovered during re-entry. Heating due to high velocity re-entry through the atmosphere is a major problem.
Safety of Classic Transport:
Much of the population of developed countries use the automobile in day to day life. Automobile accidents account for the majority of accidental deaths of all persons below the age of 75, and is the leading cause of death of people from the age 15 to 45. In the U.S. 1992 there were 31.8 million motor vehicle accidents, 39,200 died and 5.4 million were injured. Of the deaths 10.8% were non collision, 44.6% involved another motor vehicle, 16.7% a pedestrian, 27.9% a fixed object. There where 592 railway deaths, 120 airline deaths, 812 general aviation deaths, 816 recreational boating deaths, 85 commercial water deaths. The death rate per billion miles is 18 for motor vehicle, 1.3 airline, 50 for general aviation, 1.1 for train. The per billion mile death rates are slowly declining due to increasing safety measures. The per billion mile death rate for type of road: 12 urban, 26 rural, 9 interstate (6 urban, 12 rural) and 20 non interstate (14 urban, 30 rural). Many people die annually as a result of electrical shock from exposed power conductors.
Terrorist favor aircraft as a target to hijack because of the number of captive hostages. An airplane can be directed to a new destination thus providing an ideal getaway vehicle. The Automobile is often the target of criminal hijacking because of minimal security on roads and streets and the ability to elude detection (and apprehension if detected).
Speed of Classic Transport:
The current typical speeds of travel for different methods are as follows: ship 30 MPH, motor vehicle 75 MPH, fast train 200 MPH, general aviation 350 MPH, airline 600 MPH, super sonic transport 1700 MPH, space craft 18000 MPH. The speed potential of most types of travel is less than the maximums indicated because of safety needs, delays, lack of continuous service, and weather conditions.
Cost of Classic Transport:
The typical per mile cost of transport is as follows: ship 5, pleasure boat 200 c, automobile 45 c, bus 10 c, private airplane 90 c, train 15 c, airline 15 c, SST 45 c, Toll road 5 to 10 c. Total US transportation outlays for 1992 amounted to $996 billion. Freeway cost is approximately $2.5 million per mile, high speed train and rail (200 mph) $15 million per mile. The cost of a major airport is over a billion dollars. The greater the capacity of a vehicle the greater the likely hood that the full capacity cannot be fully used. If an airplane or ship is scheduled but only 1/3 full, it must honor the commitment or cancel the service, either loosing money or upsetting customers. The total economic loss due to accidents in '92 was 98.1 billion dollars. Theft and vandalism represent a large percentage of the cost of transportation losses. The environmental impact is a cost that is difficult to quantify, but clearly the automobile is a leading cause of air pollution.
Disadvantages of Classic Transport:
Land vehicles operating on roads have the following disadvantages: at the mercy of wind, rain, darkness, snow, hail, frost, and ice; rely on roads subject to wear, damage, ruts, frost heaving, washouts, potholes, mud, and rock slides; continual danger of collision with stationary or moving objects; mechanical failures including flat tires, out of gas, headlight failure, sudden catastrophic failures, and dead batteries; high maintenance cost; short life; and reliance on continual operator vigilance and skill. Trains operating on rails are subject to derailment, brake failure, track damage, objects on the track, and reduced traction in wet or icy weather. Continuos service is impractical for trains. Span loading for road and rail bridges are very high, leading to high cost.
Marine vehicles have the following disadvantages: at the mercy of wind, rain, darkness, snow, hail, frost, and ice; danger from wave action, tides and currents; Continual danger of collision with stationary or moving objects; mechanical failures including, out of fuel, leaks, engine failure, and dead batteries; danger of sinking, and drowning; high maintenance cost; short life; and reliance on operator vigilance and skill.
Aircraft have the following disadvantages: at the mercy of weather; rely on a place to land (airport) subject to wear, damage, ruts, frost heaving, washouts, potholes, and mud; Continual danger of collision with stationary or moving objects; mechanical failures including engine outage, out of fuel, sudden catastrophic failures, and radio interference; high maintenance cost; short life; and reliance on exceptional operator vigilance and skill. A collision with a single bird can cause a jumbo jet to crash.
Most transport vehicles use internal combustion engines that cause air, water, and noise pollution. Despite the disadvantages and high cost of classic transport methods, they are very widely used. Transport accounts for over 10 percent of the worlds gross product, and is growing at twice the rate. This is testament to human desire and need for transportation.
Water, oil, sewage, natural gas and other liquids and gasses are often transported by pipelines. The capacity of a pipeline is limited by the size of the pipe and the pressure available to overcome the frictional losses of the fluid. The power required varies in direct proportion with the length of the pipe. Very long pipes require many pumping stations along the pipe to overcome losses. Heat loss in long pipes prevent use to transport heat over long distances.
Electric power transport lines transport electricity from production facilities to end users. The voltage available along the line drops proportionally to the distance from the source. The voltage drop is a great power loss. The extreme voltage required to move electric energy long distances is dangerous. High towers and wide rite of ways are required to maintain safe distances from the high voltage. Sub stations are needed to reduce the voltage to lower levels for distribution. Ice and wind loads often down lines and cause fires due to arcing. High tension power lines are not compatible with road traffic because of the danger of a line tower being struck by a stray vehicle. There is much room for improvement involving classic transport; however major rethinking is required if great gains are desired.
2. Prior Art Relating to the Invention
Conveying systems that use an air pump to reduce the air pressure in front of a capsule to transport documents and money are in common use (Lang U.S. Pat. No. 5,234,292 August 1993; Podoll--Jensen U.S. Pat. No. 4,715,750 December 1987). These Pneumatic tubes are only efficient for light loads (under 5 lb.), low speed, and distance under 5 miles. A great percentage of the energy losses are due to the friction of the air moving through the tube.
Many patents disclose the use of magnetic energy to levitate a body for transport thus eliminating speed limitations caused by rolling elements (Tozoni U.S. Pat. Nos. 5,319,275 June 1994; Quaas 5,291,834 March 1994; Alcon 5,319,336 June 1994; Berdut 5,452,663; etc.). Maglev technologies are varied in complexity and efficiency. These systems do not address the substantial elimination of aerodynamic drag, or eliminate the possibility of collisions, or provide isolation from weather.
Conveying systems used in the electronics industry utilize magnetic levitation and high vacuum to reduce the possibility of contamination of parts and materials requiring dust free environments for production (Kawada et al. U.S. Pat. No. 5,309,049 May 1994). This system is unusable for high speed continuous transport, because intermittent motion is required. The efficiency is low.
A few patents disclose transportation systems using evacuated tubes to reduce or substantially eliminate aerodynamic drag. These systems have not been practical for one reason or another. Minovitch U.S. Pat. Nos. 3,954,064; 4,075,948; and 4,148,260 discloses a gravity powered system that requires a tunnel several thousand feet into the earth. While highly efficient, the system is impractical from many standpoints: it is highly stressed and requires exotic materials to build. It is susceptible to flooding. It is susceptible to geologic shifts of the earth. The alignment means are not automatic. The speed attainable is dependent on great depth or complex, heavy flywheel energy storage. The inertial load of the vehicle is not allowed for. Vibration and swaying loads are ignored. For great depths under the earth the temperature and heat flux is so great that the entire diameter of the tube would be taken by cooling water and steam escape. Sutton U.S. Pat. No. 5,513,573 is even less practical than Minovitch, as the pressure at 100 miles depth would crush a tube formed of any known material let alone solidified rock.
The system disclosed by O'neil et al. U.S. Pat. No. 5,433,155. discloses precise control and locating of trains of vehicles. The system relies on electrical energy and computer control to suspend the vehicle. A conductor is used between the vehicle and the tube. A computer failure could result in sudden suspension failure. No provision exists for active alignment of the tube.
The system disclosed by Goddard U.S. Pat. No. 2,511,979 requires large amounts of mercury which is toxic.
The vacuum highway seal (lock) disclosed by Milligan U.S. Pat. No. 5,435,253 is impractical. The high vapor pressure of water at non freezing temperatures would cause high drag. If a low vapor pressure liquid such as mercury where used, special means of containment and handling would be involved to negate the toxic nature and environmental hazard. Additionally the inventor has not done sufficient and accurate calculations. The lack of technical rigor is evidenced by the statement that "the vacuum tube would have to be restrained from floating away", this is not valid because a structure capable of withstanding a vacuum would be to heavy to float off by reason of the buoyancy in air unless constructed of exotic, delicate materials unfit for the intended purpose.
There have been a few patents issued on evacuated tubes with magnetic suspension and linear motor accelerators used to accelerate a space craft to orbital or escape velocity (Minovitch U.S. Pat. Nos. 4,791,850; 4,795,113 and Marks et al. U.S. Pat. No. 4,881,446). These systems are not usable as a mass transport system, and the acceleration energy is not recovered.
Most of these systems are batch type of systems severely limiting the capacity. The vehicle handling and terminals are not disclosed to the point of a viable mass transport system. None of the systems disclosing evacuated tubes sufficiently disclose the operation of the terminal and tube to allow high volumes of continuous traffic at high speeds. Despite the advantages of these transport systems, their incomplete execution, lack of technical accuracy, and impractical design have relegated them to obscurity. They represent forward thinking, but improvement is required to achieve practicality.
Super conductor technology offers large efficiency gains and is now cost effective in limited fields. Non super conducting linear motors have demonstrated efficiencies over 95%, thus super conductors offer at best a 5% improvement of energy utilization, at great cost. High power superconductor motors have been tested with favorable results and are nearing commercial use. Many levitation technologies depend upon the development of cost effective super conductors.
Electric power generation from nuclear or fossil fuel energy sources accounts for most of the worlds electric generation capacity. Most power plants only convert 30 to 40 percent of the energy consumed into usable electric power. The remaining 60 to 70 percent is wasted and contributes to thermal pollution.
Regenerative breaking is not a new concept. It is used in electric cars to help recharge the batteries while decelerating. In classic transport the amount of energy required to accelerate an object is small compared to the non recoverable losses. It made little sense to expend money on regenerative breaking unless the power transmission means also provided for regenerative breaking. Some electrified railway trains use regenerative breaking. The energy saved is small compared to that lost due to aerodynamic and rolling losses. Danger of electrical shock is a problem due to exposed conductors.
Airlock technology is well developed in fields such as; astronautics, sub-marine, manufacturing, etc. Those well versed in the art have developed safe efficient methods of transferring persons or goods between differing pressures and atmospheres. It will be readily apparent to those versed in the art the special requirements for the airlock means used by the present invention.
Linear motor propulsors are a highly developed field (Sink U.S. Pat. No. 5,497,038), many types exist. Electromagnetic rail gun and satellite launching technology has been initially tested with favorable results. Sandia National Laboratories has developed SERAPHIM (Cowan, et al. U.S. Pat. No. 5,552,649) using this technology to power fast trains (300 mph). Linear projectile accelerators have been demonstrated that can accelerate an object to a speed of 2 kilometers per second, it is estimated by those versed in the art that speeds of 6-8 km/sec. are possible with technology now under development. Aerodynamic drag, rolling resistance, and heating are not addressed by this technology; they are the biggest barrier to higher speeds.
Atomic particle accelerators are in use that accelerate a particle or group of particles to extremely high velocity in an evacuated environment. Electromagnetic means are used to suspend and accelerate the atomic particles. The speed of the particles is measured as a percentage of the speed of light. Atomic particle accelerators are incapable of suspending, accelerating or transporting a payload of any size to be of use as a commercial transport device.
Automatic people conveying systems are in common use. At amusement parks like Disney World the art has advanced to a high degree. These systems are optimized for low speeds. They are reliable and exhibit high continuous usage.
The Romans constructed massive aqua ducts to carry water and sewage. Many still stand and work, after 2000 years. They tunneled through mountains and built over valleys with only human and animal power, and crude measuring devices. Tunneling, road, rail, bridge, and pipeline construction techniques have advance to a high degree, but fail to address the special requirements of travel at speeds measured in miles per second vs. miles per hour.
Continuous pipe making machines are used to make fiberglass reinforced plastic pipe for the transport of fluids. The machines are not used on site so the pipe must be cut to length in the plant and rejoined in the field to construct a pipeline. This cutting and refitting wastes time, requires additional parts, and results in a greater likelihood of leaking.
Many methods of load and position sensing are available to efficiently make continuous accurate measurements at very low cost and energy expenditure. Radar, imaging, GPS, LASER, optical microprocessors, and electronic controllers are well developed technologies. Many schemes at traffic control utilizing these devices have been disclosed. These schemes are capable of increasing existing road capacity, reducing accidents, and increasing safe speed of classic transport a limited amount. They do not provide a substantial elimination of accidental collisions, only a reduction.
Lasers can be used to transmit data at rates exceeding 10 Gbites/sec. Atmospheric conditions limit the usable range for communication use. Dust, fog, and rain scatter the signal.
Life support systems using air quality and temperature monitoring and maintaining equipment are well established. Nuclear submarines and space craft rely on these systems for months at a time. Air re-breathers using similar technology are used by divers. The systems are expensive due to low volume manufacture, and lack of standardization.
None of the prior art utilize positive air and obstacle exclusion from the path of transport to reduce or eliminate aerodynamic drag and increase safety of travel, while allowing efficient continuous loading and unloading of persons and cargo. Because of aerodynamic drag and heating many advanced technologies cannot be fully exploited by the transportation industry. The extra cost of these technologies cannot be justified unless their quantum improvement potentials can be realized.
Objects and Advantages:
The present invention seeks to exploit many advantages of the listed prior art transportation technologies, while eliminating many of the disadvantages. Eliminated are: most causes of accidents, aerodynamic limitations, pollution, vulnerability to the elements, schedules, flammable fuel hazards, resource waste, energy waste, noise, operator skill requirements, wild life barriers, hijacking's, theft, and environmental damage. The present invention also seeks to use advantages of the invention to take the place of: water and sewer lines, electric transmission lines, water heaters, communications cables, communications satellites, and roads.
To maximize safety, and efficiency of travel along a planned path from point A to point B we need the following: 1) Assurance that all obstacles either are moved off of the path or will move off of the path before passage. 2) Assurance of staying on the intended path. 3) A means of accelerating from point A and decelerating to point B., 4) A means of storing or using the energy liberated upon deceleration. 5) means of safe and orderly boarding and disembarking from the path.
The present invention addresses these special needs by unique combinations of known technologies. An Evacuated Tube Transport system (ETT) solves many problems associated with classic transport by moving all obstacles from the path of travel and not allowing their return. Once the path is evacuated and free from obstacles, travel can take place unimpeded. The object traveling (in this case a capsule) is in a tube so it stays on the intended path and no obstacles can get on the path. If subsequent capsules undergo identical acceleration and deceleration, many capsules can travel the same direction in the tube at once with complete safety. Acceleration and deceleration are planned to prevent the capsule from becoming a obstacle to subsequent capsules. The reliability of the capsules is very high due to minimal or no reliance on moving parts. Most of the energy required to accelerate is recovered during deceleration. Means are provided to remove the capsules from the end of the tube or to provide space for successive capsules. Passive or active tube alignment systems keep operation smooth.
The present invention (ETT) eliminates virtually all aerodynamic drag. Current technology that minimizes or eliminates rolling resistance, hysteresis losses, and drag due to suspension, acceleration, and deceleration are exploited. ETT insures that conditions are maintained that allow safe continuous, uninterrupted flow of passengers or cargo. ETT verses classic transport offers: I) greatly increased speed for a given cost or safety level. II) Drastically reduced cost and increased safety for a given speed.
ETT can be used to transport electrical power, water, sewer, oil, gases, and used to extend the overall energy usage of existing power plants.
Challenges of ETT are mainly economic, or related to travel at ultra high speed or in an evacuated environment, they include: High capital requirements with long amortization periods (for a given speed cost can be less). As with roads and tracks, the speed potential is limited by economic considerations over difficult topography, however for a given cost and capacity speed potential is much greater than other forms of ground transport. At hyper velocities any malfunction of seals or compromise of the integrity of the tube could destroy capsules because of extreme kinetic energy, thus security of the tube gains importance as speed increases. Reliance on life support systems is a small price to pay for the many advantages produced by an evacuated environment. Once the trip has started there is no stopping or turning back (unless an emergency occurs) so human needs must be taken into consideration according to the length of the trip. Congestion at busy terminals can be minimized by limiting inflow to the capacity of the system. Some passengers may experience claustrophobia, this can be mitigated by drugs, or preferably, suitable sensory stimulation. Prolonged accelerations can cause discomfort, proper seat design can reduce this. An earth quake, mud slide, flash flood or tidal wave could damage the tube killing many of the occupants and releasing tremendous destructive energy; prudent design precautions mitigate this as known to those versed is the construction and civil engineering arts. Geological movements of the earth are mitigated by an alignment system. Failure of one of the capsules could cause the failure of many, so reliability is paramount. Failure of the braking system could result in the destruction of the terminal and all occupants of the tube, redundant systems prevent this. The challenges are surmountable, as taught by the present invention, as will become apparent to those versed in the arts upon examination of this document.
Advantages of ETT over traditional transportation methods are many; safety, efficiency, speed, convenience and ecology are the main advantages.
Safety: Potential for destruction varies as the square of velocity and linearly with mass. For a given speed the object with lighter mass is the safer. The ETT system minimizes moving mass, thus safety is greater. ETT Enables hyper velocities, hence more potential for destruction exists due to that velocity. For any given speed over about 20 mph and distances over about 10 miles ETT is the safest method of travel. Safer than walking because while in the tube it is improbable to be hit by a motor vehicle, bullet or bolt of lightning. Safer than motor vehicles because the path of travel is always under control; no collisions with a fixed object or another motor vehicle, less mechanical failure to worry about, not subject to adverse weather. Safer than trains because most train accidents are caused by something on or wrong with the track, this is virtually impossible with ETT. Safer than marine travel because of no weather exposure, and collision elimination. Safer than flying because most plane crashes are due to; bad weather, human error, or mechanical failure, all of which are drastically reduced by ETT. Impossible for children, pets, or animals to wander into the way to be run over. No fuel is carried and the materials used can be fire resistant. The major causes of accidents of classic transport have been either eliminated or drastically reduced by ETT.
Efficiency: ETT is the most cost efficient method of travel between two points on earth for traffic volume over aproximatly 12000 vehicles per day and distances over about 10 miles. At a given speed the energy usage is the lowest possible. The operating life is longer and wear and tear less than other forms of transportation, hence longer amortization is possible. Few moving parts to wear out. For a given capacity in persons per hour, the dead and live loads for a ETT bridge or span is much lower than rail or road, leading to lower costs. The separate technologies needed for the implementation of the system are already in use and well proven. The ETT does not rely on super conductor technology, but greater, capacity and efficiency are possible when superconductors become cost effective. ETT can use electricity that can be derived from renewable sources. Most of the materials used are low cost and can be recycled. Existing manufacturing capacity and methods can be used, lowering cost. Worn out roads that need replacing anyway are an ideal location for ETT. Many identical components results in economies of production. Low speed ETT systems require much less right of way because the path of travel is protected, this results in greater land use efficiency, and lower construction and maintenance cost. ETT is compatible with many existing right of ways. ETT can increase the energy conversion efficiency of an existing power plant from 30% to 40% to as much as 80% by making waste heat available to sell. ETT can augment existing communications systems for low additional cost. ETT can replace existing water and sewer pipes, offsetting some cost of construction. ETT can move ice from cold climates to hot climates to supply fresh water and refrigeration, (or waste heat to cold locations).
The energy usage of the ETT is the energy required to:
A) Evacuate the tube. At a minimum equal to A*P*L where A is the area of the cross section, P is the atmospheric pressure, L is the length of the tube (for a tube 4.5 foot dia., at standard conditions is 178 million ft. lb. per mile).
B) Evacuate any leakage.
C) Operate terminal and accessory equipment, removal of excess heat, life support system service requirements.
D) Overcome suspension hysteresis, acceleration/deceleration losses, power transmission and conversion losses, and eddy current losses. The total powering loss is estimated at 5 to 10 percent of the maximum kinetic energy of the capsules. (For a 3000 lb. loaded capsule at v=1 mi/sec total kinetic energy is 1.3 billion ft. lb. per capsule.)
E) Overcome the slight aerodynamic drag from residual gasses still in the tube. The aerodynamic drag varies with air density. A easily achieved vacuum is 0.1 Tohr, the drag reduction at this vacuum is around 5,000 to 1. A medium vacuum is one thousandth of that, or 5,000,000 to 1, a high vacuum is one thousandth of that or just 0.000000002 of the drag at one atmosphere of pressure (outer space is about one hundred thousandth of that).
F) Make up the potential energy difference between arrival and departure altitude. This can result in a net gain if the departure is higher than the destination.
For a given speed and for long distances the energy used per person or ton is less than one percent of the most efficient form of classic transport (99%+energy savings).
Speed: ETT is the fastest possible method of travel between two points on earth greater than 2 miles apart (until star trek becomes a reality). The speed is limited by human limits of acceleration tolerance, this can be minimized with fluid immersion if still greater speed is needed. The curvature of the tube determines the acceleration due to centripetal motion. Thus the speed is limited by the minimum radius to be traveled. For a straight tube the limit to top speed is determined by the linear acceleration that can be produced and the distance. As speed increases so do the energy requirements to maintain the maximum acceleration that a occupant can tolerate. The maximum speed is limited by waste heat build up in the capsule, and the amount of power that the acceleration device is rated for.
Ecology: If renewable, non fossil electricity is used the ETT is non polluting, yielding lower environmental costs. ETT is ideally suited to non polluting energy sources like; wind turbine, solar, hydroelectric. ETT can be used to transport energy, thus reducing the need for electric power transmission lines. Extremely long useful life minimizes the waste of materials associated with other forms of transport. The ETT is quiet. The impact to the environment is minimal compared to a road that animals can't cross without danger. Minimal storm water runoff impact. ETT is more than 100 times less disruptive to wet lands than a road or airport. ETT utilization results in a sustainable world transport system.
Other advantages: Virtually continuous, non-intermittent operation results in no scheduling required. No advance booking or ticket needed. Not dependent on good weather. No storm delays. Travel from any city, to any city on earth within 4 hours (after the system is built). No driver license required. Minimal training required. No fueling required. No odors or fumes produced. Huge existing market, with favorable demand trends toward faster and more efficient travel. Low market dependence, since the need of transport is basic. Servicing and operation can be automated. Light weight simplifies repair and construction. Convenience and social interaction enhanced by mechanization. Can use existing production facilities with minimal tooling cost. Obsolescence unlikely. Can use travel imbalances to transport waste. Less reliance on oil resulting in cheap plastics. Low risk proof of concept for non-life support versions can minimize initial product liability. Aerodynamic instabilities and supersonic heating are virtually eliminated.
ETT does not rely on, or improve directly upon superconductor technology. It is believed that superconductor technology will advance much faster as a result of ETT utilization. ETT can fully exploit the advantages of super conductors. There will be much more incentive to develop cost effective superconductors when ETT becomes utilized.